When a massive earthquake strikes—like the 2010 Haiti quake, which killed over 100,000 people—the international relief system springs into action. Medical personnel fly to the disaster site; food aid groups coordinate relief deliveries; and millions of people around the world dig into their pockets to send money to the victims. At least $15 billionwas donated in the wake of the Haiti quake—more than half what the U.S. government spent in 2013 on foreign aid in total.

No would doubt that victims—often injured and homeless—need immediate help after something as catastrophic as a major quake. But as Brian Tucker, the president of the earthquake consultancy GeoHazards International, points out in a piece in Science, some of that money would do far more good if it could be spent preparing a city or country before disaster strikes. “We can significantly reduce the death rate from natural disasters,” says Tucker. “But we need to increase the proportion of investment we make in preparedness.”

You can already see the difference that even a little bit of preparation for quakes—usually in the form of public education and tougher building codes—can make in human lives. The 8.8-magnitude quake that struck Chile in February 2010 killed just 0.1% of the Chileans who experienced the quake. Compare that to the 7.0-magnitude Haiti quake—11% of Haitians who were subject to the same strength of shaking died, according to modeling by the U.S. Geological Survey. Haiti is poorer than Chile—indeed, Haiti is one of the poorest countries in the world—but Chile is far from rich, with a per-capita GDP of around $18,000. The real difference is preparation. Haiti had virtually none, and shoddily-constructed buildings simply collapsed. Chile, after a devastating quake in 1960, developed and enforced a modern building code—one that saved countless lives.

In his study, Tucker—who works to better prepare countries for seismic risks—compared the lethality of all moderate quakes that occurred from 1970 through 2012, with the exception of a couple of outliers. He found that the average number of deaths per quake in each of the 10 most earthquake-prone countries was about 90 times as high as the average number of deaths per earthquake in resilient places like California, Japan and Chile. He notes that if a tsunami similar to the one that swamped northern Japan in 2011 were to strike the city of Padang in West Sumatra, Indonesia, it could kill several hundred thousands people.

Even scarier, there are some 250 million people living in cities in developing countries that are within 100 km of an earthquake fault, a number that’s been growing sharply in recent years and which far outpaces the size of developed cities in the earthquake danger zone. The challenge will be to convince developing countries—which face a dizzying array of challenges—that earthquake preparation is worth the investment. Tucker compares it to public health. Just as no one would doubt that a dollar spent on vaccines or bed nets can save more lives than a dollar spent on critical care, money that goes to earthquake prevention will be even more valuable than the relief that comes in the wake of a disaster. “The earthquake risk reduction community might ﬁnd effective lessons, models, and tactics from studying those public health campaigns,” writes Tucker.

It doesn’t take that much. Tucker points out that simple school earthquake safety could save countless lives when the next quake strikes. (When a massive quake hit western China in 2008, thousands of children died when their substandard school buildings collapsed on top of them.) But we’re not doing enough, and the next quake that strikes a poor, unprepared country will kill tens of thousands, if not more. It doesn’t have to be that way. The disaster divide isn’t permanent.